What parts of OGRE are used?

edit

We're planning a new project. Our target is also to generate high-quality pictures of our simulation world. As I've seen for example in games which use OGRE, it is possible for OGRE to render quiet nice scenes. When it comes to Gazebo the rendered scenes are good for its purpose (robot simulation) but not as good as OGRE could be.

Is there a list of missing features?

I recommend starting with high quality meshes and textures. That is the easiest thing to do in order to achieve high quality graphics.

Let use know if you are still seeing quality issues after you use nice meshes and textures.